Firstly, it's pictured from the opposite side of the house to that seen in the movie. That feels a bit wrong because you never see that side of the house in the move; I guess that does give the artist some extra room to play given that the house doesn't exist.

Still, there's definitely some problems compared to the "actual house;" for example, in the poster the front section of the house is at the same level as the back section, but in the movie it appears to be lower than the back section, though that could be an optical illusion.

More troubling is the placement of the stone structure next to the end of the front section of the house (the red line in the image above). If you compare it to the poster, the artist seems to have placed a stone column on the opposite side of the house at the same location - relative to the "front" of the house - as the column on the visible side of the house.

The problem with that is that if you look at shots of the interior of the house, you'll see that there is actually a fireplace on the opposite side of the house that extends further towards the front of the house.

This can be seen in the following images; first the left-hand side of the room, with the stone wall, windows, and first wooden column.

Note the location of the rug, which is just forward of the end of the stone column on the left-hand side of the room. Looking at the right-hand side of the room (below) there is a fireplace that extends further along that wall, well past the end of the rug.

The width of the fireplace can be seen very clearly from this angle:

So I think the poster is wrong!

But perhaps most troubling of all, is that I actually noticed this, and bothered pointing it out.